Re: Please define ROW CHAINING!!!
Date: 1995/09/27
Message-ID: <44cd3d$o3i_at_news.ios.com>#1/1
Nabil Courdy (ncourdy_at_parka.winternet.com) wrote:
: I am teaching myself -trying to at least- Oraclle. I monitor this
: newsgroup as one of my resources. Could someone please tell me
: what Row Chaining is?
Row Chaining is the method whereby Oracle tracks block overflows. Oracle
rows are variable length by design, although they may be fixed length in
practice. Since Oracle permits variable length columns (varchar, etc.),
it needs a way to allow a row to be moved if it no longer fits into a
block. A new block is allocated and the row plopped there, with a
forward pointer to it. It is a linked list.
Not very efficient, so you want to avoid it when possible.
Roger Snowden
snowden_at_haven.ios.com